These aren't of the scale of the $50 billion that Bernard Madoff is alleged to have lost, but hundreds of millions of dollars have vanished. Officials point to the cases of Arthur G. Nadel in Florida, Joseph S. Forte in Philadelphia and James Ossie in Atlanta as among the most notable allegations.

Call them mini-Madoffs.

"With the economic downturn that we are experiencing, Ponzi schemes are just crashing," said Stephen Obie, acting director of enforcement at the Commodity Futures Trading Commission.

Officials say it doesn't necessarily mean more scams are occurring, it just means that more are being exposed as scams.

The commission said the number of tips to the agency has doubled since July. In the last 12 months, it has filed 15 cases and Obie expects that to rise by 25 percent in the coming months.

"These schemes rely on new people to be found and people aren't investing. People are hurting. And because people are hurting, they are seeking redemptions from what they think are these legitimate schemes," Obie said. "Between not having new investors and having old investors redeem, the Ponzi schemes are just collapsing."

The most recent case to come to light involves Nadel, a Florida hedge fund manager who has been missing for more than a week and was charged Wednesday with misleading investors.

After the 76-year-old Sarasota-based manager's disappearance, hundreds of investors learned that $300 million of their money was gone, too.

Nadel left a suicide note at his home in which he described "extreme guilt" over losing other people's money. However, his car was found at a Sarasota airport and officials believe he planned his disappearance.

The Securities and Exchange Commission said Nadel recently transferred at least $1.25 million to secret bank accounts that he controlled.

It is quite a downfall for a man named "America's Top Ranked Money Manager" in 2003 by The Wall Street Digest, an investment newsletter.

"The community is very shocked, obviously," said Gordon Garrett, a friend of Nadel's and president of the Jazz Club of Sarasota. "Art and his wife Peg have been very prominent members of our community, very involved with the arts."

Losing Money and Misleading Investors

Garrett didn't have any money invested with Nadel's company, Scoop Management, but his group does not need to cancel eight concerts that Nadel had promised to sponsor.

Things are a little bit more grim at the local YMCA.

Neil Moody, who was a general partner in some of Scoop Management's funds, donated $1.12 million to the YMCA Foundation of Sarasota. That money makes up about 13 percent of the group's $8.6 million endowment.

Moody's first gift came in 2005 and he insisted that it be invested with one of Nadel's funds, Valhalla Management.

"The fund did not meet our investment guidelines, so he made a personal guarantee that it have a return of 10 percent, per annum," foundation president Karin Gustafson said. "He believed that that fund could outperform any other funds that were being managed for us."